1. Field of the Invention
The present invention relates to a semi-transmissive liquid crystal display device having, as a pixel electrode of a display device, in one pixel, a light transmissive pixel electrode that transmits light and a light reflective pixel electrode that reflects light, and a manufacturing method thereof.
2. Description of the Related Art
In an existing general liquid crystal display device, there are a transmissive liquid crystal display device in which a light source is disposed on a back surface or a side surface thereof to carry out image display and a reflective liquid crystal display device in which ambient light is reflected by a surface of a reflection plate formed on a substrate to carry out image display. In the transmissive liquid crystal display device, when ambient light is very bright, display light becomes darker in comparison with the ambient light; accordingly, the display cannot be observed. In order to make the display observable, the intensity of the light source has to be increased, resulting in a problem in that the power consumption increases. On the other hand, the reflective liquid crystal display device has a disadvantage in that when the ambient light is very dark, the visibility deteriorates very much. In order to overcome the problems, a liquid crystal display device (hereinafter, referred to as a semi-transmissive liquid crystal display device) that has, in one pixel, a light transmissive pixel electrode that transmits light and a light reflective pixel electrode that reflects light is proposed.
In an existing semi-transmissive liquid crystal display device, as a TFT array substrate that has, in one pixel, a light transmissive pixel electrode and a light reflective pixel electrode, a structure that includes a gate wiring that includes a gate electrode formed on a transparent insulating substrate; a source wiring that includes a source electrode intersecting through a first insulating film with the gate wiring; a thin film transistor (hereinafter, referred to as a TFT), as a switching element, which is made of a semiconductor layer formed through the first insulating film on the gate electrode, a source electrode and a drain electrode; an interlayer insulating film made of a second insulating film and an organic resin film that are formed above the TFT, the gate wiring and the source wiring; a transmissive pixel electrode made of a highly transparent conductive film electrically connected with a drain electrode of the TFT through a contact hole formed on the interlayer insulating film; and a reflective pixel electrode made of a highly reflective metal film formed without through the insulating film on the transmissive pixel electrode is disclosed (for example on pages 6-11 and FIG. 1 in JP-A-2003-248232).